:root {
    --bg-color: #000000;
    --card-bg: #0a0a0a;
    --text-main: #ffffff;
    --text-muted: #888888;
    --accent-color: #00ff88; 
    --accent-glow: rgba(0, 255, 136, 0.15);
    --border-color: #1a1a1a;
    --gradient-primary: linear-gradient(135deg, #00ff88 0%, #00d4ff 100%);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    padding: 2rem 1rem;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    animation: fadeIn 0.8s ease-out forwards;
}

header {
    margin-bottom: 2.5rem;
    padding: 10px 0;
    position: relative;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    letter-spacing: -1px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-top: 5px;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.8);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at top right, rgba(255,255,255,0.03), transparent 50%);
    pointer-events: none;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px var(--accent-glow);
    border-color: #333;
}

.kpi-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 30px;
}

.kpi {
    display: flex;
    align-items: center;
    gap: 20px;
}

.kpi-icon {
    font-size: 2.5rem;
    background: linear-gradient(135deg, rgba(0,255,136,0.1), rgba(0,212,255,0.1));
    padding: 15px;
    border-radius: 50%;
    width: 76px;
    height: 76px;
    display: flex;
    justify-content: center;
    align-items: center;
    border: 1px solid rgba(0,255,136,0.2);
    box-shadow: 0 0 20px var(--accent-glow);
}

.kpi-info h3 {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 5px;
}

.kpi-info p {
    font-size: 2.2rem;
    font-weight: 600;
    color: var(--text-main);
    text-shadow: 0 0 15px rgba(255,255,255,0.2);
}

.charts-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 24px;
    margin-bottom: 30px;
}

.chart-container {
    display: flex;
    flex-direction: column;
}

.chart-container h2 {
    font-size: 1.2rem;
    font-weight: 400;
    margin-bottom: 20px;
    color: var(--text-muted);
}

.chart-wrapper {
    position: relative;
    height: 300px;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.table-section {
    width: 100%;
}

.table-section h2 {
    font-size: 1.2rem;
    font-weight: 400;
    margin-bottom: 20px;
    color: var(--text-muted);
}

.table-responsive {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    text-align: left;
}

th, td {
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
}

th {
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

td {
    font-size: 1rem;
    color: #e0e0e0;
    transition: color 0.2s ease;
}

tr {
    transition: background-color 0.2s ease;
}

tr:hover {
    background-color: rgba(255,255,255,0.03);
}

tr:hover td {
    color: #ffffff;
}

.val-col {
    font-weight: 600;
    color: var(--accent-color);
}

/* Form Section */
.form-section {
    margin-bottom: 30px;
}

.form-section h2 {
    font-size: 1.2rem;
    font-weight: 400;
    margin-bottom: 20px;
    color: var(--text-muted);
}

#new-sale-form {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    align-items: flex-end;
}

.form-group {
    flex: 1;
    min-width: 200px;
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.form-group input,
.form-group select {
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 12px 16px;
    border-radius: 8px;
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus,
.form-group select:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 10px var(--accent-glow);
}

.btn-group {
    flex: 0 0 auto;
}

.btn-submit {
    background: var(--gradient-primary);
    color: #000;
    font-family: 'Inter', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--accent-glow);
}

.btn-delete {
    background-color: transparent;
    color: #ff4d4d;
    border: 1px solid #ff4d4d;
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: 'Inter', sans-serif;
}

.btn-delete:hover {
    background-color: rgba(255, 77, 77, 0.1);
    box-shadow: 0 0 10px rgba(255, 77, 77, 0.4);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.card {
    animation: fadeIn 0.8s ease-out backwards;
}

#card-revenue { animation-delay: 0.1s; }
#card-sales { animation-delay: 0.2s; }
#card-seller-chart { animation-delay: 0.3s; }
#card-product-chart { animation-delay: 0.4s; }
#card-sales-history { animation-delay: 0.5s; }

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-color);
}
::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #555;
}

/* Responsiveness */
@media (max-width: 768px) {
    body {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .charts-section {
        grid-template-columns: 1fr;
    }
    
    .kpi-cards {
        grid-template-columns: 1fr;
    }
    
    .kpi-icon {
        width: 60px;
        height: 60px;
        font-size: 2rem;
    }
    
    .kpi-info p {
        font-size: 1.8rem;
    }
}